Resonant cavity strained iii-v photodetector and led on silicon substrate

ABSTRACT

An optoelectronic device that includes a germanium containing buffer layer atop a silicon containing substrate, and a first distributed Bragg reflector stack of III-V semiconductor material layers on the buffer layer. The optoelectronic device further includes an active layer of III-V semiconductor material present on the first distributed Bragg reflector stack, wherein a difference in lattice dimension between the active layer and the first distributed brag reflector stack induces a strain in the active layer. A second distributed Bragg reflector stack of III-V semiconductor material layers having a may be present on the active layer.

BACKGROUND

Technical Field

The present disclosure relates to photodetectors and light emittingdevices (LEDs), and more particularly to extending photodetection inphotodetectors to long wavelengths and extending light emission fromLEDs to long wavelengths on silicon substrate.

Description of the Related Art

Photodetectors are broadly defined as devices which respond to incidentelectromagnetic radiation by converting the radiation into electricalenergy, thereby enabling measurement of the intensity of the incidentradiation. A photodetector typically includes some sort ofphotoconductive device and external measurement circuitry.

Light emitting diodes can be broadly defined as devices which respond toelectrical energy with emission of light. For example, a light-emittingdiode (LED) is a two-lead semiconductor light source. It is a p-njunction diode, which emits light when activated. When a suitablevoltage is applied to the leads, electrons are able to recombine withelectron holes within the device, releasing energy in the form ofphotons. This effect is called electroluminescence, and the color of thelight (corresponding to the energy of the photon) is determined by theenergy band gap of the semiconductor.

SUMMARY

In one embodiment, the present disclosure provides a photodetectorcomprising a germanium containing buffer layer atop a silicon containingsubstrate. A first distributed Bragg reflector stack of III-Vsemiconductor material is present on the germanium containing bufferlayer. An absorption layer of III-V semiconductor material is present onthe first distributed Bragg reflector stack of Ill-V semiconductormaterial, wherein a difference in lattice dimension between theabsorption layer and the first distributed Bragg reflector stack ofIII-V semiconductor material induces a strain in the absorption layer. Asecond distributed Bragg reflector stack of Ill-V semiconductor materialis present on the absorption layer. The strain induced on the absorptionlayer provides that the photodetector detects light wavelengths greaterthan 800 nm.

In another embodiment, the present disclosure provides a light emittingdiode comprising a germanium containing buffer layer atop a siliconcontaining substrate. A first distributed Bragg reflector stack of III-Vsemiconductor material is present on the germanium containing bufferlayer. A light emission layer of III-V semiconductor material is presenton the first distributed Bragg reflector stack of III-V semiconductormaterial, wherein a difference in lattice dimension between the lightemission layer and the first distributed brag reflector stack of Ill-Vsemiconductor material induces a strain in the light emission layer. Asecond distributed Bragg reflector stack of III-V semiconductor materialis present on the light emission layer. The strain induced on theemission layer provides that the light emitting diode emits lightwavelengths greater than 800 nm.

In another aspect of the present disclosure, a method of forming anoptoelectronic device is provided. In some embodiments, the method maybegin with forming a buffer layer of a germanium containing layer on asilicon containing substrate. A first distributed Bragg reflector stackof III-V semiconductor material having a first conductivity type isformed on the buffer layer. An active layer is epitaxially formed on thefirst distributed Bragg reflector stack of III-V semiconductor material,wherein a different in lattice dimension between the active layer andthe first distributed Bragg reflector induces a strain in the activelayer. A second distributed Bragg reflector stack of III-V semiconductormaterial having a second conductivity type is formed on the activelayer. The active layer functions as an absorption layer of aphotodetector that detects wavelengths greater than 800 nm when aforward bias is applied to the optoelectronic device. The active layerfunctions as an emission layer of a light emitting diode that emitswavelengths greater than 800 nm when a reverse bias is applied to theoptoelectronic device.

These and other features and advantages will become apparent from thefollowing detailed description of illustrative embodiments thereof,which is to be read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

The disclosure will provide details in the following description ofpreferred embodiments with reference to the following figures wherein:

FIG. 1 is a side cross-sectional view of a resonant cavityoptoelectronic device, e.g., a resonant cavity photodetector or aresonant cavity light emitting diode, which includes a strained typeIII-V active layer positioned between first and second distributed Braggreflector stack of III-V semiconductor material, in accordance with oneembodiment of the present disclosure.

FIG. 2 is a side cross-sectional view depicting depositing a germaniumcontaining buffer layer on a silicon containing substrate, in accordancewith one embodiment of the present disclosure.

FIG. 3 is a side cross-sectional view depicting forming a firstdistributed Bragg reflector stack of III-V semiconductor material on thegermanium containing buffer layer, in accordance with one embodiment ofthe present disclosure.

FIG. 4 is a side cross-sectional view depicting epitaxially depositingan active layer of a III-V semiconductor material on the firstdistributed Bragg reflector stack of III-V semiconductor material,wherein a difference in lattice dimension between the active layer andthe first distributed Bragg reflector stack induces a strain in theactive layer.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

The present principles provide resonant cavity optoelectronic devices,such as photodetectors and light emitting diodes, in which the activematerial layer of the resonant cavity optoelectronic device is astrained, e.g., tensile strained or compressively strained, type III-Vsemiconductor material. As used herein, the term “resonant cavity” asused to describe an optoelectronic device, such as a light emittingdiode (LED) or photodetector, denotes that the active layer of theoptoelectronic device is present inside a Fabry-Perot resonant cavity.This means that the active layer for the optoelectronic device may bepresent between two mirrored surfaces. In some embodiments, the twomirrored surfaces may each include a Bragg mirror, which is alsoreferred to as distributed Bragg reflector. A distributed Braggreflector is a mirror structure which consists of an alternatingsequence of layers of two different optical materials. One design isthat of a quarter-wave mirror, where each optical layer thicknesscorresponding to one quarter of the wavelength for which the mirror isdesigned. The latter condition holds for normal incidence; if the mirroris designed for larger angles of incidence, accordingly thicker layersare needed. The principle of operation for the Bragg reflector can beunderstood as follows. Each interface between the two materialscontributes a Fresnel reflection. For the design wavelength, the opticalpath length difference between reflections from subsequent interfaces ishalf the wavelength; in addition, the amplitude reflection coefficientsfor the interfaces have alternating signs. Therefore, all reflectedcomponents from the interfaces interfere constructively, which resultsin a strong reflection. The reflectivity achieved is determined by thenumber of layer pairs and by the refractive index contrast between thelayer materials. The reflection bandwidth is determined mainly by theindex contrast.

In some embodiments, the active layers are epitaxially formed on atleast one of the material layers that provide one of the distributedBragg reflectors, in which the material compositions for the distributedBragg reflector and the active layers result in a difference in latticedimensions. The difference in lattice dimension induces a strain in theactive layer of the optoelectronic device. In some embodiments, usingthin layer strained type III-V semiconductor material on a latticemismatched silicon containing substrate, e.g., silicon substrate,extends the photodetection performance of a photodetector to longwavelengths on the order of 850 nm or greater. In some embodiments,using thin layer strained type III-V semiconductor material on a latticemismatched silicon containing substrate, e.g., silicon substrate,extends the light emission performance of light emitting diodes (LEDs)to wavelengths on the order or 850 nm or greater. Additionally, theresonant cavity can help to enhance the photodetection and lightemission using a thin layer of material, which can be grownsubstantially free of defects on the silicon containing substrate.Further details regarding the optoelectronic devices, and methods offorming optoelectronic devices are now provided with reference to FIGS.1-4.

It is to be understood that the concepts of the present disclosure willbe described in terms of a given illustrative structure; however, otherstructures, substrate materials and process features and steps may bevaried within the scope of the present disclosure. It will also beunderstood that when an element such as a layer, region or substrate isreferred to as being “on” or “over” another element, it can be directlyon the other element or intervening elements may also be present. Incontrast, when an element is referred to as being “directly on” or“directly over” another element, there are no intervening elementspresent. It will also be understood that when an element is referred toas being “connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present. References in the specification to “oneembodiment”, “an embodiment”, “an example embodiment”, etc., indicatethat the embodiment described may include a particular feature,structure, or characteristic, but every embodiment may not necessarilyinclude the particular feature, structure, or characteristic. Moreover,such phrases are not necessarily referring to the same embodiment.Further, when a particular feature, structure, or characteristic isdescribed in connection with an embodiment, it is submitted that it iswithin the knowledge of one skilled in the art to affect such feature,structure, or characteristic in connection with other embodimentswhether or not explicitly described.

FIG. 1 depicts one embodiment of a resonant cavity optoelectronic device100, e.g., a resonant cavity photodetector or a resonant cavity lightemitting diode, which includes a strained type III-V active layer 20positioned between first and second distributed Bragg reflector stack ofIII-V semiconductor material layers 15, 25. In one embodiment, theoptoelectronic device 100 includes a germanium containing buffer layer10 atop a silicon containing substrate 5, and a first distributed Braggreflector stack of III-V semiconductor material layers 15 on the bufferlayer. The optoelectronic device 100 may further include an active layer20 of III-V semiconductor material present on the first distributedBragg reflector stack 15, wherein a difference in lattice dimensionbetween the active layer 20 and the first distributed Bragg reflectorstack 15 induces a strain in the active layer 20. In the embodiments inwhich the optoelectronic device 100 is a photodetector, the active layer20 includes an absorbing layer, and in the embodiments in which theoptoelectronic device 100 is a light emitting diode (LED), the activelayer 20 is an emission layer. A second distributed Bragg reflectorstack 25 of III-V semiconductor material layers may be present on theactive layer 20.

In one embodiment, the silicon containing substrate 5 may be abulk-semiconductor substrate. In one example, the bulk-semiconductorsubstrate may be composed substantially entirely of silicon, e.g.,greater than 97 at. % silicon (Si). In some embodiments, the siliconcontaining substrate 5 is greater than 99 at. % silicon (Si). In otherembodiments, the silicon containing substrate 5 is 100 at. % silicon(Si). Other illustrative examples of Si-containing materials suitablefor the silicon containing substrate 5 include, but are not limited to,Si, SiGe, SiGeC, SiC, polysilicon, i.e., polySi, epitaxial silicon,i.e., epi-Si, amorphous Si, i.e., α:Si, and multi-layers thereof.Although not depicted in FIG. 1, the silicon containing substrate 5 mayalso be a semiconductor on insulator (SOI) substrate. In someembodiments, the silicon containing substrate 5 may be lighttransmissive. The term “light transmissive” or “light transmitting”denotes that the material allows for the transmission of light therethrough. For example, a light transmissive substrate may allow forvisible light, e.g., light having a wavelength of approximately 400 nmto approximately 700 nm, to be transmitted there through. In oneexample, the light transmissive substrate may have a refractive indexthat is equal to approximately n=1.5.

The germanium containing buffer layer 10 may be an epitaxially formedsemiconductor layer. In some embodiments, the buffer layer provides forgradual change in lattice dimension as a transition from the siliconcontaining substrate 5 to the overlying distributed Bragg reflectorstack of III-V semiconductor material layers 15. The germaniumcontaining buffer layer 10 may have a final germanium (Ge) contentranging from about 0.1 to about 100 at. %. The germanium containingbuffer layer 19 may have a thickness of about 2000 nm or less, with athickness from about 10 to about 100 nm being more highly preferred. Thegermanium containing buffer layer 19 is substantially free of defects.When the optimal conditions are employed, the germanium containingbuffer layer 19 has a defect density that is less than about 1000defects/cm².

In one example, the germanium containing buffer layer 19 and thesubstrate 5 may be provided by a germanium on insulator (GOI) substrate.

The first distributed Bragg reflector stack 15 of type III-Vsemiconductor material may be epitaxially formed on the germaniumcontaining buffer layer. The term “type III-V semiconductor” denotes asemiconductor material that includes at least one element from GroupIIIA of the Periodic Table of Elements and at least one element fromGroup VA of the Periodic Table of Elements. Typically, the III-Vcompound semiconductors are binary, ternary or quaternary alloysincluding III/V elements. Examples of III-V semiconductor materialssuitable for use with the present disclosure, e.g., use in the first andsecond distributed Bragg reflector stack 15, 25 and the active layer 20,include (AlSb), aluminum arsenide (AlAs), aluminum nitride (AlN),aluminum phosphide (AlP), gallium arsenide (GaAs), gallium phosphide(GaP), indium antimonide (InSb), indium arsenic (InAs), indium nitride(InN), indium phosphide (InP), aluminum gallium arsenide (AlGaAs),indium gallium phosphide (InGaP), aluminum indium arsenic (AlInAs),aluminum indium antimonide (AlInSb), gallium arsenide nitride (GaAsN),gallium arsenide antimonide (GaAsSb), aluminum gallium nitride (AiGaN),aluminum gallium phosphide (AlGaP), indium gallium nitride (InGaN),indium arsenide antimonide (InAsSb), indium gallium antimonide (InGaSb),aluminum gallium indium phosphide (AlGaInP), aluminum gallium arsenidephosphide (AlGaAsP), indium gallium arsenide phosphide (InGaAsP), indiumarsenide antimonide phosphide (InArSbP), aluminum indium arsenidephosphide (AlInAsP), aluminum gallium arsenide nitride (AlGaAsN), indiumgallium arsenide nitride (InGaAsN), indium aluminum arsenide nitride(InAlAsN), gallium arsenide antimonide nitride (GaAsSbN), gallium indiumnitride arsenide aluminum antimonide (GaInNAsSb), gallium indiumarsenide antimonide phosphide (GaInAsSbP), and combinations thereof.

The first distributed Bragg reflector stack 15 of type III-Vsemiconductor material may be lattice matched to the germaniumcontaining buffer layer 10. In some embodiments, the first distributedBragg reflector stack 15 includes an alternating sequence of two typeIII-V semiconductor material compositions. For example, the first typeIII-V semiconductor material layer 15 a of the first distributed Braggreflector stack 15 that is in direct contact with the germaniumcontaining buffer layer 10 may be composed of Al_(0.2)Ga_(0.8)As, andthe second type III-V semiconductor material layer 15 b of the firstdistributed Bragg reflector stack 15 may be composed ofAl_(0.1)Ga_(0.9)As, in which the first and second type III-Vsemiconductor material layers 15 a, 15 b are present in an alternatingsequence through the first distributed Bragg reflector stack 15. In oneembodiment, the first distributed Bragg reflector stack 15 may becomposed of 10 to 30 layers of alternating composition type III-Vsemiconductor layers. In another embodiment, the first distributed Braggreflector stack 15 may be composed of 15 to 25 layers of alternatingcomposition type III-V semiconductor layers. Each of the type III-Vsemiconductor material layers in the first distributed Bragg reflectorstack 15 may have a thickness ranging from 5 nm to 30 nm. In anotherembodiment, each of the type III-V semiconductor material layers in thefirst distributed Bragg reflector stack 15 may have a thickness rangingfrom 10 nm to 25 nm.

The term “conductivity type” denotes that a semiconductor material hasbeen doped to provide an p-type or n-type conductivity. In someembodiments, the first distributed Bragg reflector stack 15 has beendoped to an n-type conductivity and the second distributed Braggreflector stack 25 has been doped to a p-type conductivity. For typeIII-V semiconductor materials, an n-type dopant may be provided by anelement from Group IVA or VIA of the Periodic Table of Elements, and ap-type dopant may be provided by an element from Group IIA or VIA of thePeriodic Table of Elements.

Similar to the germanium containing buffer layer 20, the firstdistributed Bragg reflector stack 15 may be substantially free ofdefects. For example, when the optimal conditions are employed, thefirst distributed Bragg reflector stack 15 has a defect density that isless than about 1000 defects/cm².

Still referring to FIG. 1, the active layer 20 of type III-Vsemiconductor material may be epitaxially formed on the firstdistributed Bragg reflector stack 15. In the embodiments in which theoptoelectronic device 100 is forward biased, the optoelectronic device100 functions as a light emitting diode, wherein at least a portion,e.g., intrinsic active layer 20 a, of the active layer 20 is an emissionlayer. In the embodiments, in which the optoelectronic device 100 isreverse biased, the optoelectronic device 100 functions as aphotodetector, wherein at least a portion, e.g., intrinsic active layer20 a, of the active layer 20 is an absorbing layer.

The active layer 20 is epitaxially formed having a composition thatprovides a different lattice dimension than the upper surface of thefirst distributed Bragg reflector stack 15. The difference in latticedimension between the active layer 20 and the first distributed Braggreflector stack 15 induces a strain within the active layer 20. Forexample, the strain induced in the active layer 20 may be a compressivestrain ranging from 0.5% to 5%. The strain induced within the activelayer 20 increases the wavelengths that are sensed/emitted by theoptoelectronic device 100. In one embodiment, when the optoelectronicdevice 100 is a photodetector, the wavelength of light that can bedetected may be greater than 850 nm. In some examples, the wavelength oflight that can be detected by the resonant cavity strained III-Vphotodetector may be equal to 1.5 microns, 1.55 microns, 1.6 microns,1.65 microns, and 1.7 microns. The wavelength of light that can bedetected by the resonant cavity strained III-V photodetector may also beany value within a range defined by a lower limit and upper limitselected from the aforementioned examples.

In another embodiment, when the optoelectronic device 100 is a lightemitting diode (LED), the wavelength of light that can be emitted may begreater than 850 nm. In some examples, the wavelength of light that canbe emitted by the resonant cavity strained III-V LED may be equal to 1.5microns, 1.55 microns, 1.6 microns, 1.65 microns, and 1.7 microns. Thewavelength of light that can be emitted by the resonant cavity strainedIII-V LED may also be any value within a range defined by a lower limitand upper limit selected from the aforementioned examples.

In one example to provide the difference in lattice dimension forinducing a strain in the active layer 20, the active layer 20 may becomposed of In_(0.53)Ga_(0.47)As, and the surface of the firstdistributed Bragg reflector stack 15 that the active layer 20 is formedon may be composed of one of Al_(0.2)Ga_(0.8)As, and Al_(0.1)Ga_(0.9)As.The active layer 20 may have a thickness ranging from 5 nm to 30 nm. Inanother embodiment, the active layer 20 may have a thickness rangingfrom 10 nm to 25 nm.

In some embodiments, the active layer 20 may be substantially defectfree. For example, when the optimal conditions are employed, the activelayer 20 can have a defect density that is less than about 1000defects/cm².

In some embodiments, the active layer 20 is an intrinsic type III-Vsemiconductor material. In some embodiments, the intrinsic type III-Vsemiconductor material 20 a is centrally positioned in the active layer20; a first conductivity doped portion 20 b, e.g., n-type doped portion,of the active layer 20 is positioned proximate to the interface betweenthe active layer 20 and the first distributed Bragg reflector stack 15;and a second conductivity doped portion 20 c, e.g., p-type dopedportion, of the active layer 20 is positioned proximate to the interfacebetween the active layer 20 and the second distributed Bragg reflectorstack 25.

Similar to the first distributed Bragg reflector stack 15, the seconddistributed Bragg reflector stack 25 may be composed of type III-Vsemiconductor material that can be substantially lattice matched to thegermanium containing buffer layer 10. In some embodiments, the seconddistributed Bragg reflector stack 25 includes an alternating sequence oftwo type III-V semiconductor material compositions. For example, thefirst type III-V semiconductor material layer 25 a of the seconddistributed Bragg reflector stack 25 that is in direct contact withactive layer 20 may be composed of Al_(0.2)Ga_(0.8)As, and the secondtype III-V semiconductor material layer 25 b of the second distributedBragg reflector stack 25 may be composed of Al_(0.1)Ga_(0.9)As, in whichthe first and second type III-V semiconductor material layers 25 a, 25 bare present in an alternating sequence through the first distributedBragg reflector stack 25. In one embodiment, the second distributedBragg reflector stack 25 may be composed of 10 to 30 layers ofalternating composition type III-V semiconductor layers. In anotherembodiment, the second distributed Bragg reflector stack 25 may becomposed of 15 to 25 layers of alternating composition type III-Vsemiconductor layers. Each of the type III-V semiconductor materiallayers in the second distributed Bragg reflector stack 25 may have athickness ranging from 5 nm to 30 nm. In another embodiment, each of thetype III-V semiconductor material layers in the second distributed Braggreflector stack 25 may have a thickness ranging from 10 nm to 25 nm.

Although not depicted in FIG. 1, the optoelectronic device 100 mayfurther includes electrodes, such as cathode and anodes that can bepositioned at substantially opposing ends of the device. The electrodesmay be composed of indium tin oxide or a metal.

In another aspect of the present disclosure, a method of forming anoptoelectronic device 100 is provided. In some embodiments, the methodmay begin with forming a buffer layer of a germanium containing layer 10on a silicon containing substrate 5, as depicted in FIG. 2. The bufferlayer of the germanium containing layer 10 may be formed using anepitaxial deposition process. The terms “epitaxial growth and/ordeposition” means the growth of a semiconductor material on a depositionsurface of a semiconductor material, in which the semiconductor materialbeing grown has substantially the same crystalline characteristics asthe semiconductor material of the deposition surface. The term“epitaxial material” denotes a material that is formed using epitaxialgrowth. In some embodiments, when the chemical reactants are controlledand the system parameters set correctly, the depositing atoms arrive atthe deposition surface with sufficient energy to move around on thesurface and orient themselves to the crystal arrangement of the atoms ofthe deposition surface. Thus, in some examples, an epitaxial filmdeposited on a {100} crystal surface will take on a {100} orientation.

A number of different sources may be used for the epitaxial depositionof the semiconductor material that forms the buffer layer of thegermanium containing layer 10. For example, germanium containingprecursors for epitaxial deposition may include germanium gas selectedfrom the group consisting of germane (GeH₄), digermane (Ge₂H₆),halogermane, dichlorogermane, trichlorogermane, tetrachlorogermane andcombinations thereof.

It is noted that deposition is only one method that is applicable forforming the germanium containing layer 10. The germanium containingbuffer layer 10 may be transferred to the silicon containing substrate 5using layer transfer and bonding methods. Additionally, the germaniumcontaining layer 10 and the silicon containing substrate may be providedby a preformed germanium on insulator (GOI) substrate. In this example,a dielectric layer may be present between the germanium containingbuffer layer 10 and the silicon containing substrate 5.

FIG. 3 depicted one embodiment of forming a first distributed Braggreflector stack 15 of III-V semiconductor material layers on thegermanium containing buffer layer 10. Similar to the germaniumcontaining buffer layer 10, the first distributed Bragg reflector stack15 may be formed using epitaxial deposition. A number of differentsources may be used for the deposition of epitaxial type III-Vsemiconductor material. In some embodiments, the sources for epitaxialgrowth of type III-V semiconductor material include solid sourcescontaining In, Ga, and As elements and combinations thereof. Theprecursor gasses are selected and sequenced to provide a latticedimension for the first type III-V semiconductor material layer 15 a andthe second type III-V semiconductor material layer 15 b of the firstdistributed Bragg reflector stack 15 that is substantially equal to thelattice dimension of the germanium containing buffer layer 10. In oneembodiment, the gas precursors for epitaxially forming the first typeIII-V semiconductor material layer 15 a are selected to provideAl_(0.2)Ga_(0.8)As, and the gas precursors for epitaxially forming thesecond type III-V semiconductor material layer 15 b are selected toprovide Al_(0.1)Ga_(0.9)As.

In some embodiments, at least a portion of the first distributed Braggreflector stack 15 is doped to an n-type conductivity. The n-type dopantmay be introduced to the first distributed Bragg reflector stack 15in-situ. By “in-situ” it is meant that the dopant that dictates theconductivity type of the III-V semiconductor material layers of thefirst distributed Bragg reflector stack 15 is introduced during theprocess step, e.g., epitaxial deposition that forms the III-Vsemiconductor material layers of the first distributed Bragg reflectorstack 15. In other embodiments, the first distributed Bragg reflectorstack 15 may be doped using ion implantation or gas phase doping.

FIG. 4 depicts one embodiment of epitaxially depositing an active layer20 on the first distributed Bragg reflector stack 15 of III-Vsemiconductor material. The epitaxial deposition process for forming theactive layer 20 is similar to the epitaxial deposition process describedabove for forming the first distributed Bragg reflector stack 15 withthe exception that the composition of the III-V semiconductor materialfor the active layer provides a different lattice dimension than thelattice dimension of the III-V semiconductor material of the firstdistributed Bragg reflector stack 15. The lattice dimension of thematerial of the first distributed Bragg reflector stack 15 issubstantially equal to the lattice dimension of the germanium containingbuffer layer 10. In one embodiment, the epitaxial deposition processforms an active layer that is composed of In_(0.53)Ga_(0.47)As. Thedifferent in lattice dimension between the active layer 20 and the firstdistributed Bragg reflector 15 induces a strain in the active layer 20.

The active layer 20 typically includes an intrinsic portion. Thisportion of the active layer 20 is not doped with a p-type or n-typedopant. In-situ doping may be employed to provide an n-type dopantregion at the interface of the active layer 20 and the first distributedBragg reflector stack 15. In-situ doping may also be employed to providea p-type dopant region at the interface of the active layer 20 and thesecond distributed Bragg reflector stack 25.

Referring to FIG. 1, a second distributed Bragg reflector stack 25 ofIII-V semiconductor material may then be formed on the active layer 20.The second distributed reflector stack 25 is formed using similarepitaxial deposition methods to the deposition methods used to form thefirst distributed Bragg reflector stack 15. Epitaxial deposition may beused to provide a first type III-V semiconductor material layer 25 a ofthe second distributed Bragg reflector stack 25 that is in directcontact with active layer 20 that is composed of Al_(0.2)Ga_(0.8)As, andthe second type III-V semiconductor material layer 25 b of the seconddistributed Bragg reflector stack 25 that is composed ofAl_(0.1)Ga_(0.9)As. The second distributed Bragg reflector stack 25 maybe in situ doped to a p-type conductivity.

The active layer functions as an absorption layer of a photodetectorthat detects wavelengths greater than 800 nm when a forward bias isapplied to the optoelectronic device. The active layer functions as anemission layer of a light emitting diode that emits wavelengths greaterthan 800 nm when a reverse bias is applied to the optoelectronic device.

Having described preferred embodiments of a device and method for aresonant cavity strained III-V photodetector and LED on siliconsubstrate (which are intended to be illustrative and not limiting), itis noted that modifications and variations can be made by personsskilled in the art in light of the above teachings. It is therefore tobe understood that changes may be made in the particular embodimentsdisclosed which are within the scope of the invention as outlined by theappended claims. Having thus described aspects of the invention, withthe details and particularity required by the patent laws, what isclaimed and desired protected by Letters Patent is set forth in theappended claims.

1. A photodetector comprising: a germanium including buffer layer atop a silicon including substrate; a first distributed Bragg reflector stack of III-V semiconductor material layers present on the germanium including buffer layer; an absorption layer of III-V semiconductor material present on the first distributed Bragg reflector stack of III-V semiconductor material, wherein a difference in lattice dimension between the absorption layer and the first distributed Bragg reflector stack of III-V semiconductor material layers induces a strain in the absorption layer; and a second distributed Bragg reflector stack of III-V semiconductor material layers present on the absorption layer, wherein the strain induced on the absorption layer provides that the photodetector detects light wavelengths greater than 800 nm.
 2. The photodetector of claim 1, wherein the first distributed Bragg reflector stack is doped to a first conductivity type, and the second distributed Bragg reflector stack is doped to a second conductivity type.
 3. The photodetector of claim 1, wherein absorption layer is intrinsic, a first conductivity type doped region is present between the absorption layer and the first distributed Bragg reflector stack, and a second conductivity type doped region is present between the absorption layer and the second distributed Bragg reflector stack.
 4. The photodetector of claim 3, wherein the first conductivity type is n-type and the second conductivity type is p-type.
 5. The photodetector of claim 1, wherein a lattice dimension for the III-V semiconductor material in the first distributed Bragg reflector stack and a second distributed Bragg reflector stack is substantially equal to the lattice dimension of the germanium including buffer layer.
 6. The photodetector of claim 1 wherein at least one of the first and second distributed Bragg reflector is comprised of at least one of Al_(0.2)Ga_(0.8)As and Al_(0.1)Ga_(0.9)As, and the absorption layer is comprised of Al_(0.1)Ga_(0.9)As.
 7. A light emitting diode comprising: a germanium including buffer layer atop a silicon including substrate; a first distributed Bragg reflector stack of III-V semiconductor material present on the germanium including buffer layer; a light emission layer of III-V semiconductor material present on the first distributed Bragg reflector stack of III-V semiconductor material, wherein a difference in lattice dimension between the light emission layer and the first distributed brag reflector stack of III-V semiconductor material induces a strain in the light emission layer; and a second distributed Bragg reflector stack of III-V semiconductor material present on the light emission layer, wherein the strain induced on the light emission layer provides that the light emitting diode emits light wavelengths greater than 800 nm.
 8. The light emitting diode of claim 7, wherein the first distributed Bragg reflector stack is doped to a first conductivity type, and the second distributed Bragg reflector stack is doped to a second conductivity type.
 9. The light emitting diode of claim 7, wherein the light emission layer is intrinsic, a first conductivity type doped region is present between the light emission layer and the first distributed Bragg reflector stack, and a second conductivity type doped region is present between the light emission layer and the second distributed Bragg reflector stack.
 10. The light emitting diode of claim 8, wherein the first conductivity type is n-type and the second conductivity type is p-type.
 11. The light emitting diode of claim 7, wherein a lattice dimension for the III-V semiconductor material in the first distributed Bragg reflector stack and a second distributed Bragg reflector stack is substantially equal to the lattice dimension of the germanium including buffer layer.
 12. The light emitting diode of claim 7 wherein at least one of the first and second distributed Bragg reflector is comprised of at least one of Al_(0.2)Ga_(0.8)As and Al_(0.1)Ga_(0.9)As, and the light emission layer is comprised of Al_(0.1)Ga_(0.9)As.
 13. A method of an optoelectronic device comprising: forming a germanium including buffer layer on a silicon including substrate; forming a first distributed Bragg reflector stack of III-V semiconductor material on the germanium including buffer layer; epitaxially forming an active layer on the first distributed Bragg reflector stack of III-V semiconductor material, wherein a different in lattice dimension between the active layer and the first distributed Bragg reflector stack induces a strain in the active layer; and forming a second distributed Bragg reflector stack of III-V semiconductor material on the active layer.
 14. The method of claim 13, wherein the active layer functions as an absorption layer of a photodetector that detects wavelengths greater than 800 nm in response to a forward bias applied to the optoelectronic device
 15. The method of claim 13, wherein the active layer functions as an emission layer of a light emitting diode that emits wavelengths greater than 800 nm in response to a reverse bias applied to the optoelectronic device.
 16. The method of claim 13, wherein the first distributed Bragg reflector stack is in situ doped to a first conductivity type, and the second distributed Bragg reflector stack is in situ doped to a second conductivity type.
 17. The method of claim 13, wherein active layer is intrinsic, an in situ doped first conductivity type doped region is present between the active layer and the first distributed Bragg reflector stack, and an in situ doped second conductivity type doped region is present between the absorption layer and the second distributed Bragg reflector stack.
 18. The method of claim 17, wherein the first conductivity type is n-type and the second conductivity type is p-type.
 19. The method of claim 13, wherein a lattice dimension for the III-V semiconductor material in the first distributed Bragg reflector stack and a second distributed Bragg reflector stack is substantially equal to the lattice dimension of the germanium including buffer layer.
 20. The method of claim 13, wherein at least one of the first and second distributed Bragg reflector stack is comprised of at least one of Al_(0.2)Ga_(0.8)As and Al_(0.1)Ga_(0.9)As, and the active layer is comprised of Al_(0.1)Ga_(0.9)As. 